The cellular immune response against extracts from the individual corneal layers and lens was studied in guinea pigs and rabbits. Purified T-cells from guinea pig peritoneal exudates and rabbit popliteal lymph nodes were used. Employing the blast transformation phenomenon, which is considered the in vitro counterpart to the anamestic response in vivo, a comparison was made as to the relative immunogenicity and antigenicity of various ocular extracts. Epithelium was found to be a strong immunogen in vivo and antigen in vitro, while endothelium was least active using the same criteria. Stroma showed intermediate activities. Species specific antigens were found in all corneal layers. Strong organ specificity was exhibited by the lens.